The first roundabout I ever saw was in my neighborhood of Sugarhouse in Salt Lake City. It was fairly small, and replaced a 4 way intersection. As you approached it there was a sign that said "Traffic Circle" which created some confusion in my mind as to whether it should be called a roundabout or a traffic circle.
It turns out the two terms are not for the same thing. Traffic Circles are larger and do no require you to yield before entering. Roundabouts are smaller, and you must yield before you enter. The traffic is slower on roundabouts than traffic circles, making them safer.
In the last decade we have seen an explosion of roundabouts and I like them. They are safer and faster than normal intersections.